Question about Vortech flow scaling

[jccaclimber]

I have two MP40w pumps, one in use on a 75 set to lagoonal, and the other being saved for a future tank upgrade. On higher power settings I can see them cycle. On the min power setting, even on reef crest mode, it seems like it just hums at a constant speed. Is this just my perception?

To try to clarify my question I've attached a plot. I've used sine waves to make the point clearer. Say the pump is set to a max power of 100% (blue line). It is cycling between 10% and 100% power (may not be 10%, I just picked a number). If I turn down the pump to a max power of 20%, does it cycle between 10% and 20% (red line) or 20% and a lower number (say 2%, black line)? Extending that question, if the pump is set to min power is it still going operating at changing RPMs, or just running constant at the min speed no matter the mode?

 

[Breadman03]

The dial sets your desired maximum to anywhere from the pump minimum speed to the maximum speed. The pump will then run that graph between the pump minimum and your set maximum. If you set the max to the pump minimum, the result will be a steady speed.

 

[jccaclimber]

So following that, a smaller pump running closer to max speed will be better than one large one running turned down (assuming you want more variation)? Is that why they have a min,max, and "optimal" range in their sizing tool?

I'm also weighing an MP10 in a 14g biocube. Width of outflow aside, it sounds like it won't be a lot different than a steady state pump in that application. Perhaps a bit worse since I actually view all three sides of that tank and don't really want a cord on the outside.

 

[Alex Y EcoTech]

jccaclimber,

That is correct, the higher your assigned max speed the more speed variation you will have.